The third-largest Internet service provider said it is testing a new permission-based spam-blocking technology and plans to roll it out to subscribers by the end of May.
The company said it will argue to shut down what it calls a Buffalo, New York, spam ring that sent more than 825 million unwanted e-mails since March 2002 over EarthLink's networks to its subscribers. The hearing is scheduled for Wednesday in U.S. District Court in Atlanta.

EarthLink alleges that Howard Carmack, who. the ISP calls the "Buffalo Spammer," along with his accomplices, used stolen credit cards, identity theft, banking fraud and other illegal activities, to fraudulently purchase Internet accounts and send spam. EarthLink claims that Carmack assumed the identities of other Carmack family members and of innocent third-parties to disguise his own involvement in these illegal activities.

Spam is the bane of the Internet. By taking legal measures to shut down a spammer like Carmack, EarthLink can help preserve the Internet experience for all consumers, not just EarthLink subscribers," said Pete Wellborn, EarthLink's legal counsel who led the investigation, in a statement. "With the Buffalo spammer, EarthLink is continuing its tradition of using state and federal laws to stop spammers.

Other Internet companies, such as America Online, Microsoft's MSN and Yahoo, have also been fighting spam. AOL and Microsoft recently filed suit separately against individuals and companies that are allegedly blasting spam to their members. EarthLink has previously taken legal action against other spammers.

As in its previous legal cases, EarthLink is asking for injunctive relief that will prevent Carmack from illegally spamming any Internet user, regardless of the user's ISP. EarthLink is also seeking $16 million in damages.

Most Internet service providers and e-mail services offer technologies to block spam. But in a cat-and-mouse game, the spammers regularly figure out how to bypass the blocks.

EarthLink said that, at this time, 40 percent to 70 percent of all incoming e-mail hitting its mail server is spam. The company uses Brightmail's antispam filtering tool called "the spaminator" to filter out much of that spam before it reaches its subscribers in-box. But as the spammers tweak their messages, a greater number of e-mails are able to bypass filters.

To thwart this adaptive maneuvering, EarthLink said it will roll out its new SpamBlocker technology later this month. Using a permission-based system, SpamBlocker automatically generates an e-mail in response to all incoming mail. The original sender must then respond to a question in that e-mail before the message is delivered to its intended recipient. Once authorized, that person's e-mail is placed on a permitted list.

EarthLink said it will continue to use its spaminator technology, unleashing the SpamBlocker on e-mail that gets passed through the filter.

"Filters can only work so effectively before you wind up blocking almost every piece of e-mail," an EarthLink spokesman said.